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A. T. ARNOLD & F. F. EMORY.

{No Model.)

PISTON HEAD FOR STEAM ENGINES.

Patented Dec. 30, 1884.

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N. prrcns. Phnhrlillwgnq UNITE STATES ATFNT rrrcn.

ADNEY T. ARNOLD AND FRANCIS F. EMORY, OF FITOHBURG, MASS.

PISTON-HEAD FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 309,918, dated December30, 1884.

Application filed July 14, 1884.

.Zi'b-mZZ whom it may concern.-

Be it known that we, ADNEY T. ARNOLD and FRANCIS F. EMORY, both ofFitchburg, in the county of \Vorcester and Commonwealth ofMassachusetts, have invented certain new and useful Improvements inAdjustable Piston-Heads forSteam-Engines; and we do hereby declare thefollowing to bea full, clear, and exact description of 13118831138,reference being had to the accompanying drawings, forming a part of thisspecification, in which Figure 1 represents an end view of a pistonheadwith our improvement applied thereto. Fig. 2 represents a centralsection on line A B, Fig. 1; and Fig. 3 represents a sect-ion on line CD, Fig. 2.

The nature of our invention consists in the CO111bl11l1ZlOl1 Of thepiston-head with the piston-rod, whereby the piston-head can be adjustedbodily up or down indcpendentlyofthe piston-rod to which it is attached,as will be hereinafter more fully described.

To enable those skilled in the art to which our invention belongs tomake and use the same, we will proceed to describe it morein detail.

In the drawings, the part marked E represents a section of a piston-rodthe end E of which is made tapering or in conical form o from the pointa to the point b, while from the shoulder b projects a bolt part, F,with a screw-thread cut thereon to receive the fastening-nut F.

G is aspider, which, with its attached parts, forms the piston-head, andwhich spider is provided with a rim, G, and a central projecting part,II. To the outer end of the spider is secured a circular plate orcap-piece. I, provided with a circular shoulder, d, which fits insidethe flange G, and is held in place by means of screwbolts 6, whose headsenter recesses in the cap-piece I, so that when they are screwed upfirmly into position their heads will be inside the face of thecap-piece I, the screw parts of bolts 6 entering screw-holes formed inthe projecting part H, as fully indicated in full and dotted lines inthe drawings. A hole, f, is cut in the inner side of the spider G, ofsufficient size to allow the spider to slip over the largest part of theconical end of the I (No model.)

piston-rod, whereby said spider can be re moved and replaced, asdesired. A rectangular opening, J, is formed in the projecting part H,through which the conical part of the pistonrod projects, and withinthis rectangular opening are fitted two saddles, KK. The inner faces ofthese saddles are curved and inclined or tapered to correspond to thetapering or conical part of the piston-rod, as fully indicated in Fig. 2of the drawings; and after these saddles are slipped into place setscrews or bolts g are inserted through the sides of proj ection H, atright angles to the piston-rod, and screwed down upon the saddles K, asmore fully indicated in Fig. 2 of the drawings, thereby holding thepiston-head securely in its adjusted position. Check-nuts /L areemployed upon the bolts 9 to keep them from working loose. The back sideof the spider or piston-head G is grooved out, as shown at i, to receiveone side of the collar L, which is forged upon or otherwise permanentlyand securel y fastened to the piston-rod, and against which collar thespider or piston-head Gis forced and clamped when holding-nut F isscrewed or turned into position, as indicated.

in Fig. 2 of the drawings.

In fitting the spider or piston-head G to receive the respective partsused in combination therewith holes are drilled through theflange G andthence into the projection H, to receive said bolts 9. After such holeshave been drilled and tapped out in the projection H the holes in theflange G can be plugged up, thereby making the head steam and watertight.

Packing-rings m, of any of the usual forms, may be employed in thegrooves in the outer face of the piston-head G and cap I, as indicatedin Fig. 2.

From the foregoing description it will be seen that if the piston-heador the bottom of the cylinder wears, by simply removing cap I andloosening bolts or set-screws g and holding-nut F, the piston-head canbe raised or lowered, thereby readj usting it independently of thepiston-rod, which is left in its normal position in the center of thecylinder, thereby overcoming the objections to the forms of constructionin use prior to our invention.

It will be observed by those skilled in the art to which our inventionbelongs that the conical end of the piston-rod is so securely clampedand held by the saddles K that the piston-head cannot move out of place,even though holding-nut F should be loosened. Then, again, by the use ofour invention there is no danger of the cylinder ever becomingshouldered, since the piston-head can always be adjusted independentlyof the piston-rod and can be run out over the counterbore of thecylinder at each extreme end of its stroke.

If preferred, the projecting part 1-! may be made so as to contain threeor more saddles, with accompanying screws or bolts 9, said saddles beingarranged, of course, at equal distances apart, although we prefer thearrangeinent shown in the drawings.

Having described our improvements in ad- 20 justable piston-heads, whatWe claim as new,

and desire to secure by Letters Patent, is-

ADNEY T. ARNOLD. FRANCIS F. EMORY.

Witnesses to signature of A. T. Arnold:

Gulls. D. GAY,

. HENRY L. MILLER.

.Vitnesses to signature of F. F. Emory:

Tiros. H. DODGE, CHAS. D. GAY.

